Chinook salmon losing genetic diversity

Chinook salmon, an iconic species in the Pacific Northwest, have lost up to two-thirds of their genetic diversity over the past 7000 years, researchers report. The finding underscores a long-held concern that future salmon populations are imperiled by a combination of stream habitat loss, overfishing, dams, and the release of millions of fingerlings from hatcheries—even as the fish try to respond to climate change and ocean acidification.

“It’s a fascinating report,” says Matthew Sloat, a fisheries ecologist with the Wild Salmon Center, a nonprofit salmon conservation group in Portland, Oregon. “The main conclusion is not terribly surprising,” he says, but “it does confirm a long-standing guess that there has been a broad loss of genetic diversity in the [Columbia River] Basin.”

Genetic diversity is often key to enabling a species to adapt to changing environmental conditions. In salmon, for example, some individuals or populations might carry genes that make them less susceptible to new diseases or warming seas, enabling the species to survive the loss of other genetic strains.

One Response to Chinook salmon losing genetic diversity

There is an important new book about our wild salmon by Langdon Cook of Seattle. Upstream: Searching for Wild Salmon from River to Table. And of course Jay Nicholas will soon be out with his 2 volume set Salmon Fishers Journal. If we want to continue fly fishing for these magnificent fish, we need to learn everything we can about their perilous existence to better advocate for them.